安卓开发之自定义SeekBar竖立类（顺时针逆时针旋转90度）

来源：互联网发布：c语言中的continue 编辑：程序博客网时间：2024/05/15 08:08

类名：VerticalSeekBar

public class VerticalSeekBar extends SeekBar{private boolean mIsDragging;    private float mTouchDownY;    private int mScaledTouchSlop;    private boolean isInScrollingContainer = false;    public boolean isInScrollingContainer()    {        return isInScrollingContainer;    }    public void setInScrollingContainer(boolean isInScrollingContainer)    {        this.isInScrollingContainer = isInScrollingContainer;    }      float mTouchProgressOffset;    public VerticalSeekBar(Context context, AttributeSet attrs, int defStyle)    {        super(context, attrs, defStyle);        mScaledTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();    }    public VerticalSeekBar(Context context, AttributeSet attrs)    {        super(context, attrs);    }    public VerticalSeekBar(Context context)    {        super(context);    }    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh)    {        super.onSizeChanged(h, w, oldh, oldw);    }    @Override    protected synchronized void onMeasure(int widthMeasureSpec,int heightMeasureSpec)    {        super.onMeasure(heightMeasureSpec, widthMeasureSpec);        setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());    }    @Override    protected synchronized void onDraw(Canvas canvas)    {    //顺针旋转90度，        canvas.rotate(90);        canvas.translate(0, -getWidth());        //逆时针旋转90度        //canvas.rotate(-90);        //canvas.translate(-getHeight(), 0);//以原点纵坐标设置为负(滑块高度)        super.onDraw(canvas);    }    @Override    public boolean onTouchEvent(MotionEvent event)    {        if (!isEnabled())        {            return false;        }        switch (event.getAction())        {            case MotionEvent.ACTION_DOWN://按下                if (isInScrollingContainer())                {                    mTouchDownY = event.getY();                }                else                {                    setPressed(true);                    invalidate();                    onStartTrackingTouch();                    trackTouchEvent(event);                    attemptClaimDrag();                    onSizeChanged(getWidth(), getHeight(), 0, 0);                }                break;            case MotionEvent.ACTION_MOVE://移动                if (mIsDragging)                {                    trackTouchEvent(event);                }                else                {                    final float y = event.getY();                    if (Math.abs(y - mTouchDownY) > mScaledTouchSlop)                    {                        setPressed(true);                        invalidate();                        onStartTrackingTouch();                        trackTouchEvent(event);                        attemptClaimDrag();                    }                }                onSizeChanged(getWidth(), getHeight(), 0, 0);                break;            case MotionEvent.ACTION_UP://抬起                if (mIsDragging)                {                    trackTouchEvent(event);                    onStopTrackingTouch();                    setPressed(false);                }                else                {                    onStartTrackingTouch();                    trackTouchEvent(event);                    onStopTrackingTouch();                }                onSizeChanged(getWidth(), getHeight(), 0, 0);                invalidate();                break;        }        return true;    }    private void trackTouchEvent(MotionEvent event)    {        final int height = getHeight();        final int top = getPaddingTop();        final int bottom = getPaddingBottom();        final int available = height - top - bottom;        int y = (int) event.getY();                        float scale;        float progress = 0;               if (y > height - bottom)        {            scale = 0.0f;        }        else if (y < top)        {            scale = 1.0f;        }        else        {            scale = (float) (available - y + top) / (float) available;            progress = mTouchProgressOffset;        }        final int max = getMax();        progress = progress + scale * max;        progress = max - progress;//顺时针旋转90度使用，逆时针旋转90度屏蔽此段        setProgress((int) progress);    }    /**     * 按下     */    void onStartTrackingTouch()    {        mIsDragging = true;    }    /**     * 松开     */    void onStopTrackingTouch()    {        mIsDragging = false;    }    private void attemptClaimDrag()    {        ViewParent p = getParent();        if (p != null)        {            p.requestDisallowInterceptTouchEvent(true);        }    }    @Override    public synchronized void setProgress(int progress)    {        super.setProgress(progress);        onSizeChanged(getWidth(), getHeight(), 0, 0);    }}

XML中：

在Activity中使用：

private VerticalSeekBar verticalSeekBar = null;

verticalSeekBar = (VerticalSeekBar)findViewById(R.id.verticalSeekBar);
verticalSeekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener()
{
@Override
public void onStopTrackingTouch(SeekBar seekBar){}

@Override
public void onStartTrackingTouch(SeekBar seekBar){}

@Override
public void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser)
{
TextView tv= (TextView)findViewById(R.id.textview1);
tv.setText(Integer.toString(progress));
}
});

PS：类中设置的是滑块控件顺时针旋转90度。

如图，白框为屏幕区域，红色为控件，按照原点逆时针旋转90度后，已经不在屏幕显示区域了，需要将控件平移。

//getHeight()为控件高度，getWidth()为控件宽度

顺时针旋转90度：

canvas.rotate(90);
canvas.translate(0, -getWidth());//右移一个控件宽度

progress = max - progress;

逆时针旋转90度:

canvas.rotate(-90);//逆时针旋转90度

canvas.translate(-getHeight(), 0);//下移一个控件高度

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